Unlocking our sixth sense with brain magnets

Joseph Kirschvink and Nelly Ben Hayoun

Dr. Joseph Kirschvink can’t shoot rays from his wrists. As far as we know. He’s known as ‘the real Iron Man’ because he discovered that human brains contain tiny bits of magnets. In this Cosmic Chat, the out-of-this-world Nelly Ben Hayoun explores our sixth sense with the maverick geologist

Here on planet Earth, we live surrounded by an ever-present geomagnetic field. Bacteria sense this. Algae and animals sense this. It’s easy to observe that migratory birds and trout clearly sense this. And Dr. Joseph Kirschvink, who is known for his cutting-edge explorations, more than senses this.

Because, in 1992, he proved that people have a sixth sense – for magnetism. Our brains might sense Earth’s magnetic field just like birds do. It’s just a shame we can’t fly.

Magnetite is our most magnetic mineral, and you can spot it in action, if you know where to look. Just like a magnetic tape might record music, bacteria produce tiny crystals of magnetite that leave their mark, recording their direction thanks to their local magnetic field. You can see tiny compass needles in ancient rock formations, trapped in rocks.

While we know that magnetite guides bacteria and some animals, but what is one of the hardest metals on Earth doing in the human brain?

In the early 1980s, researchers began throwing their pets into magnetic detectors to see if they had magnetic properties. (Yes, really.) After completing a Ph.D. in geology at Princeton University in 1981, Dr. Kirschvink returned to Caltech to build a special laboratory for studying biomagnetism, to do things properly.

In the 1990s. the then 38-year-old geobiologist recorded the brain waves and activity of a group of volunteers in California, monitoring their brain activity in a special chamber, using EEG and creating magnetic fields with electromagnetic coils. The experiment mimicked the magnetic field changes we are subject to when we move about in the real world. example, it points vertically downwards, into the ground, at the magnetic north pole.

Together with a multidisciplinary team of geoscientists and neurobiologists, the pioneering scientist discovered something unusual in the human brain that the world wasn’t ready for, thanks to a distinct brainwave pattern: magnetic crystals that looked just like the tiny magnets in magnetotactic bacteria. This magnetite could not have been created inorganically.

This is a big deal. Why we have magnetite in our brains at all is still a mystery, but the insights can help us understand that we respond to the Earth’s magnetic field without knowing it –  and more about the origin of life on Earth, and elsewhere in the universe. 

Joseph Kirschvink

Here, Joseph Kirschvink joins award-winning designer Nelly Ben Hayoun to talk about beautiful bacteria – and why mud is his atomic jam

Nelly Ben Hayoun: I’m excited to speak to you, Joe. As a geologist and geophysicist, you have been responsible for some incredible discoveries, even including the origin of life. I am fascinated by the relationship between magnetite and biology, and specifically the human brain. Not many people know that a lot of animals have got magnetoreception. So, tell us a bit more about our sixth sense and this incredible research you’re doing in the lab. 

Joseph: Thanks Nelly. The human brain is simply a mammalian brain, very much like any other species of mammal. Yes, we can control our bodies with it and we have hands with opposable thumbs and things, but fundamentally, our vision, our hearing, our taste or smell, all of our primary senses are more or less the same as our animal relatives. We are animals, just a different species. Many other animals use the magnetic field. We’ve known this for about 60 or 70 years. The scientific community was skeptical at first, simply because biologists couldn’t figure out how something as weak as the magnetic field might end up controlling a sensory modality.

If you go back to the literature back in the 1960s, the guy who discovered bat sonar, Don Griffin, said flatly in his review of bird navigation, that there are no magnetic materials and animals, therefore they can’t detect the magnetic field. Well, it turns out that assumption was wrong. There are magnetic materials and animal tissues that are created biochemically. If you look at tissues very carefully with very sensitive magnetometers you can find magnetic crystals inside tissues. Little magnets have been a component of the biosphere for all three and a half billion years ago. And it’s part of us. One of their functions is navigation. It’s how birds find their ways. Honey bees can detect a little magnetic anomaly as easily as vision or sight or odor. We have that same sense.

Nelly: That’s something I wanted to talk to you about actually – the origins of life itself – and the idea that to some level, magnetite could be a sign that there is life on Mars or other planets. There is this phenomenon, a fringe hypothesis, called panspermia, which says that life exists throughout the universe and came to Earth because of a collision with an asteroid that was perhaps bringing life with it. Are you a believer that there was life on a rock that impacted Planet Earth before it was even there – in the form of magnetite? Is that correct?

Joseph: More or less! What you want is a good biomarker, a biosignature, something that is difficult to make inorganically. Nobody can make the equivalent of these magnetite crystals that we find in bacteria and in fish, and in us. Life has sculpted them. Life forms inside the cells, crystallising them to be perfect magnets. It aligns the crystal structures in the given orientation, it elongates these nanometer-sized crystals in one crystallographic direction, quite usually, it is a fingerprint. And the thing that makes this interesting for me, is that these are tiny fossils. They can be preserved in meteorites and other planets, and in meteorites from other planets. In fact, one of the oldest meteorites we have from Mars, about 4.2 billion years old, has little limestone blebs. And it’s inside is limestone webs, or mineral fossils of magnetite, or mineral crystals that have all of these features. We don’t know how to make them inorganically.


Nelly: What you are saying is mind-expanding! Most of us believe that crystals, or in this case, magnetite crystals, are dead things. But what you’ve just said is actually these are made by life. And that these crystals are also in our brain. I mean, that is pretty phenomenal.

Joseph: It’s interesting. You know, most biologists and electrical engineers, for example, ignore this discovery. We discovered this 30 years ago. And dozens of other studies have followed up and replicated it. They may be linked to Alzheimer’s disease, there may be other links to things that look like traumatic brain injury from strong fields. But fundamentally, this means humans are part of Earth’s magnetic biosphere. For three-and-a-half billion years, the Earth has had the ability to tune and respond to the GMO grid field. That’s a lot of time for evolution to act. And we’re just now starting to unravel what the role of this material might be. Some of it is a compass, but there may be other things. The magnetic field next to one of these crystals is enormous. It’s up to half a Tesla in the membrane surrounding these modern day crystals. Weird chemical reactions that normally don’t occur, can occur. They’re things that depend on magnetic fields. So it’s a whole new game of biochemistry. 

Nelly: Talking of games, I found out that there is actually a really fun bacteria called magnetotactic bacteria. (That’s difficult to say as a French person!) How do they work?

Joseph: Magnetotactic bacteria are the most beautiful living organisms on Earth, a little bacteria, dots under a microscope. But when you get them together, millions and billions of them, and put a magnet there, they’ll all swim the same direction. You can turn the magnet, and they’ll swim the other way. So you can control billions of living things with a simple bar magnet. It’s just fantastic. Wow. And they’re all over the bacterial domain. They’re beautiful. You can go to almost any pond, where there’s maybe a duck pond and lilies, take a mason jar, just scoop up some mud and put a magnet next to the side. And after half an hour or so, you can see this happen. I published a whole paper doing this. Now there are hundreds of papers on this.

You can control billions of living things with a simple bar magnet.

Nelly: So, everyone at home can just do that. You just need a magnet from your fridge, and then go pick up some mud and find these magnetotactic bacteria. If you have a microscope, you can then study them. You can just scratch a bit of the mud when they glue on the magnets and just look at it on a microscope. And just to be clear, everyone, when you do this you actually are looking at the very origins of life. 

Joseph: We can actually go and probe the genes that make these magnetite crystals. These things are ancestral to the ancestral bacteria. That puts it back three and a half billion years, or maybe earlier. It’s quite plausible they came from Mars. Martian fossils are 404 million years old. These things could be running remnants of some of the first living organisms.

Nelly: So we talked about some level of experiment that we can do at home with mud. But, more epicly, you proved that we have magnetite crystals in the brain. So we have a magnetic sensor. You did something that I thought was quite interesting. You stuck a student inside a darkroom of your laboratory and you basically put electrodes all over his brain. Am I right?

Joseph: I didn’t take the skull off to put things in the brain! But yeah!

Nelly: Am I correct in thinking that you then exposed him to magnetic fields, and studied how his brain was reacting to it?

Joseph: Here’s the thing. Most physicists in the past that who have tried to look at magnetic sensors in animals took what’s called the ‘dumb physicist’ approach. They cranked up a big magnetic field so it isn’t too weak or difficult for the animal to detect. Of course, from the point of view of an animal with lots of magnetite crystals, suddenly there’s this huge magnet. It wonders what to do and decides to ignore it, because it knows it’s not a natural signal. So what we did is, we set up an experiment where we could move the magnetic field relative to the person, just the same as you would turn your head, the same strength. But instead of turning your head, we turn the magnetic field. We do it in a silent box with beautiful controls that nobody can hear and test. You move the magnetic field and see if the brain responds. And dang it, it has! We discovered the brain responding to magnetic fields that are ecologically relevant.

Nelly: And that’s how you made that amazing discovery. I also love the idea that in the Magnetic Field Laboratory in Caltech right now, it’s all autonomous. Your magnets are now doing their own little kind of work on their own, connecting with the magnetic field of planet Earth. Thank you so much, Joe. Let’s encourage everyone to play with magnetotactic bacteria at home.

What’s so good about this?

Organisms similar to Earth’s magnetotactic bacteria may have inhabited other planets in our solar system. As we begin to understand them in our brains, we may also be able to answer whether the magnetite observed in the Martian meteorite may be biotic in origin as well.

More controversially, could the electromagnetic fields from power lines or appliances be capable of having biological effects on humans, like creating cancers? While the presence of magnetite could be a vestige from evolution and serve no purpose, it could also play a role in explaining why certain odd blips show up on magnetic resonance images of the brain.

Meet Nelly Ben Hayoun

Faster-talking than the speed of light, louder than a sonic boom and sparkier than a volcano, award-winning director and experience designer Nelly Ben Hayoun has simulated all of the above with Nelly Ben Hayoun Studios, which is considered one of the world’s best design studios. Her University of the Underground is a tuition-free charity with board members such as Pussy Riot, Noam Chomsky and Massive Attack, and her new “alien festival”, Tour de Moon, encourages creativity within the nightlife sector. Check out the Bowie-lover’s The Nelly Boum Show on Worldwide FM, where the French space enthusiast catapults us through her flights of fancy-made-real in mind-blowing, imagination-sparking conversations like this one.

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